Pentax released the K-5 IIs at the same time as the K-5 II. It's the exact same camera except for one intriguing difference: as Nikon did with the D800 and D800E, Pentax removed the low-pass filter for the IIs. Everything else on the camera is the same, but the image quality should be quite different.
When it comes to handling, the K-5 IIs is identical to the K-5 II. That means it's also nearly identical to the K-5. Even when you navigate through the menus it's hard to see what's changed. The only new thing we could find in the menu was the AF area expansion option. If you already own a K-5 then you'll know that it's a dense, weather-resistant body. People with big hands sometimes find it too compact, especially around the grip, but most should appreciate the size.
The display is the same one you find on any Pentax SLR, from the K-r all the way to the 645D. It's an LCD with fairly good resolution (920,000 dots) and convenient viewing angles. The screen is configured the same way as the K-30, with slightly cold overtones and accurate colours (though not as accurate as the EOS 650D).
For the most part the K-5 IIs is indeed a close copy of its excellent predecessor, with a clear and intuitive interface and advanced custom settings, although we still wish there were a separate button for filming rather than having to switch into video mode before you can start shooting.
Responsiveness is not an area where the K-5, K-5 II and K-5 IIs differ greatly. All three cameras give the same results, with one exception. The burst mode is back, too, taking JPEGs and RAWs alike at 4.5 fps over more than twenty consecutive shots.
But these similar figures to the K-5 (at least using the latest firmware) hide a further evolution: the K-5 II and IIs focus better in low lighting, often detecting subjects and focusing in conditions in which the K-5 simply would have given up. The difference isn't mind-blowing, but if you're used to the K-5 then you should notice the difference. However, the coverage and number of collimators in the Pentax module could still use improvement, having been bettered two years ago already by the D7000.
This is where the K-5 IIs and K-5 II differ. In theory, the absence of a low-pass filter should enable the IIs to capture better detail, but also cause more moiré-type interference problems.
The sensitivity on the IIs is excellent, as is to be expected from the 16-Mpx CMOS sensor. In terms of noise, compared to the K-5 II the difference is negligible. But the image on the IIs is sharper at low sensitivity, as you can see in the circuits on the video card shown above. And yet, we tested the II and IIs using the same lens (not just the same model—the same actual lens) and settings. And what we saw was effectively the result of having no low-pass filter, which increases the resolution by more effectively separating neighbouring pixels.
As one would expect, in this image we see the colour aberrations from the 18-55mm WR wide-angle lens. What's important to note here is the details in the lines: on the K-5 II there's a slight trace of interference before the lines disappear just below the 8, whereas on the IIs the lines continue above the 8, but with an oblique tilt that shouldn't be there! This is clearly caused by interference between the lines and the sensor's matrix.
You can also see the contrast between the II and IIs in this section of the test scene. The no-filter version on the left shows moiré on the circuits that isn't there on the image on the right. On the other hand, the vertical lines are sharper and there's more detail (the writing on the component on the lower right, the angles on the lower left...) where on the K-5 II version it's just blurry.
Perhaps the place you can see the benefits of removing the filter the most is in the texture on this book cover. The K-5 IIs provides more detail than 24-Mpx cameras such as the Alpha 77 (a direct competitor) and even the Nikon D600.
Like the K-5 II, the K-5 IIs films in Full HD if you set it to do so and encodes videos in MJPEG, a slightly antiquated codec with far less quality per MB than H.264, a file format that has become the norm among the competition.
The video image isn't terrible, the granular noise stays in check and the contrast, while a tad high, is perfectly fine... But the stereo sound is all over the place compared to today's standards. We highly suggest using an external microphone—thank heavens for the stereo in!
Two years ago the K-5 suffered from video quality that fell behind even certain compacts. The K-5 II and IIs haven't made any improvements in that arena and are now, quite simply, out of date. So we decided we're not making an exception anymore: we hereby strip the K-5 IIs of its five-star rating.